1. Field of the Invention
The present invention relates to a head gimbal assembly and an information recording and reproducing apparatus that records and reproduces various kinds of information on and from a recording medium using a focused spot beam.
2. Related Art
In recent years, a recording medium (hereinafter referred to as a disk) such as a hard disk of a computer device is facing a need for realizing recording and reproduction of high-volume and high-density information and having a further higher density is being demanded. Therefore, in order to minimize the influence of neighboring magnetic domains or thermal fluctuation, disks having strong retention force have begun to be used. Therefore, it has been difficult to record information on such disks.
In order to solve inconveniences such as those mentioned above, an information recording and reproducing apparatus has been proposed which uses a hybrid magnetic recording method of locally heating magnetic domains using near-field light to weaken the retention force temporarily and writing data to a disk during the temporary period. Particularly, the use of near-field light enables heating an area that is equal to or smaller than the wavelength of light which was regarded as a limit in a conventional optical system. Therefore, it is possible to achieve a higher density exceeding the number of recordable bits of a magnetic recording and reproducing apparatus of the related art.
An information recording and reproducing apparatus using the hybrid magnetic recording method is proposed in a variety of forms. One example thereof is an information recording and reproducing apparatus in which a light guiding portion guides light from a light source at an outer side of a slider and supplies the light to a near-field optical head provided on the slider, thus generating sufficiently large near-field light from a very small optical aperture. Therefore, the information recording and reproducing apparatus is capable of realizing superhigh-resolution and high-speed recording and reproduction and a high SN ratio. In this information recording and reproducing apparatus, the slider having the near-field optical head scans over the disk to be positioned at a desired position on the disk. Thereafter, information can be recorded on the disk by the collaboration of the near-field light radiated from the near-field optical head and a recording magnetic field generated from the slider. Among such apparatuses, there is known a configuration in which the near-field optical head is disposed at a tip end surface (trading edge) side of the slider in order to decrease the distance between the disk surface and the near-field optical head further.
As a configuration for supply a light flux to the near-field optical head, as disclosed in JP-A-2008-310865 or JP-A-2009-4006, a structure is known in which the slider and the light guiding portion are fixed to a suspension in which a notch or an optical aperture is formed, and the light flux emitted from the light source is guided to the near-field optical head by the light guiding portion.
However, in the information recording and reproducing apparatus using the hybrid magnetic recording method disclosed in JP-A-2008-310865 and JP-A-2009-4006, the suspension does not have structures, such as a flexure or a tongue portion, which is indispensable for properly maintaining a very small flying height. Therefore, it is difficult with such a structure to properly control the pressure that suppresses the air bearing force of the slider. In addition, there is a possibility that the recording and reproducing operation is not performed stably.
Meanwhile, the information recording and reproducing apparatus disclosed in JP-A-2008-130165 has a suspension structure which has a flexure or a tongue portion. Therefore, it is possible to stably levitate the slider. However, the light guiding portion or the slider must be disposed on the tongue portion which is easily deflectable in the thickness direction thereof. Therefore, there was a problem in that it is difficult to dispose the light guiding portion or the slider.
In addition, in the information recording and reproducing apparatus disclosed in JP-A-7-192421, a positioning mechanism is provided to both the slider and the tongue portion in order to facilitate disposition of the slider on the tongue portion which is easily deflectable in the thickness direction. However, in an information recording and reproducing apparatus using the hybrid magnetic recording method, it is necessary to dispose optical components such as an optical fiber or a laser unit in addition to the slider. Moreover, in many cases, such optical components have a small surface size on a surface facing the tongue portion. Therefore, there was a problem in that the optical components are likely to roll over the tongue portion when they are mounted on the tongue portion, and positioning of the optical components is difficult.